//字符串和任意类型做 +
//其他类型做 +
//字符串和任意的类型做 + 之外的
/*
let s1 = "你好" + "中国";
let s2 = "你好" + 110;
let s3 = "你好" + true;
let s4 = "你好" + undefined;
let s5 = "你好" + null;
console.log(s5)*/

/*
let num1 = 10 + "中国";
num1 = 10 + 10;
num1 = 10 + true; //boolean 和数据  boolean会转成数据 true = 1 false = 0
num1 = 10 + null;
console.log(num1)*/

let age;
// console.log('pink老师age岁啦');       // 这样不行哦
/*
console.log('pink老师' + age);          // pink老师18
console.log('pink老师' + age + '岁啦');
console.log(`pink老师${age}`)
console.log(`pink老师${age}岁了`)*/
age = 1;


console.log(typeof age)